When attempting to split a pipe the following error sometimes occurs:"Specified cast is not valid."
An "unhandled exception" error may also appear after this, and a duplicate pipe is also added to the model which cannot be seen or selected.
This situation has been known to occur if the pipe has an invalid value populated in a User Data Extension (UDX) field. For example a UDX with Integer data type with a null (blank) entry can cause this.
Examine the User Data Extensions for your pipes (Tools > User Data Extensions > Pipe) and their respective data type (integer, text, etc) then add them to the pipe Flextable and examine the values (try sorting ascending/descending). If you see any situations that need to be fixed (such as the aforementioned case of a blank value for an integer field), enter valid values or global edit by multi-selecting (use CTRL or the shift key to select all the offending cells) and right clicking on one cell and choosing "global edit". After valid values are populated for the pipe user data extensions, the issue with splitting pipes should no longer occur.
To fix the cases where this issue occurred and left behind a duplicate pipe, go to File > Database Utilities > Synchronize Drawing. The duplicate pipe (with the same label) should now be visible to select and delete if needed. The "duplicate pipes" Network Navigator query can assist with finding such cases (where two or more pipes have the same start and stop nodes).
Note: this will be investigated by the Development team for possible future improvement. Reference # 807346